EP-PS No. 256,694 discloses an infusion set of the above type. This infusion set comprises a cannula housing, in which the membrane is placed relatively far down in the through passageway in the cannula housing, a passageway between the membrane and the end facing away from the cannula forming a guide for the needles to be inserted through said membrane. The entire infusion set is shaped in a substantially rotationally symmetrical manner about the longitudinal central axis of the through passageway.
WO 88/03816 discloses an infusion set with a membrane secured at the inlet to the through passageway through the cannula housing. The membrane is retained between a beaded or melted down portion of the material of the cannula housing and a bushing arranged immediately inside the membrane and forming a conical inlet to the continued portion of the through passageway to the cannula. This infusion set is also shaped in a substantially rotationally symmetrical manner about the longitudinal central axis of the through passageway.